Archive for April, 2010

Thursday, April 29th, 2010


The new MarkLogic developer site is up, cleaner, better organized, and more social. Even cooler, it’s an XSLT-heavy application running on a pre-release version of MarkLogic. The new blog gives some of the details of the new site and transition.

So, if you’re already a MarkLogic developer, this is a great resource. And if you’re not, the site itself shows how fast and simple it is to put together a XSLT and XQuery-powered app. -m

Sunday, April 25th, 2010

Bananas Foster in a glass

The 60th anniversary of the creation of Bananas Foster is around the corner, and the project I started this weekend should be ready just in time. I’m keeping the recipe under wraps for now, but it involves ripe bananas, a particularly buttery variety of honey, brown sugar, homemade caramel, vanilla, and cinnamon. This should turn out to be a 3 gallon batch when all is said and done. It smells amazing in the primary. -m

Monday, April 19th, 2010

The Rick Wakeman clause?

Phrase seen in this article about whether video games are art, and Roger Ebert’s opinions thereon.

“Video games by their nature require player choices, which is the opposite of the strategy of serious film and literature…”

Hmm, Mr. Ebert doesn’t seem to be up on the concept of hypertext, which has manifold connections with cinema. See for instance the scholarly paper Cinematic Paradigms for Hypertext. In fact, making a hypertext or branching narrative requires even greater amounts of authorial skill.

But I’m still curious, what is the Rick Wakeman clause? From where did that term originate? -m

Sunday, April 18th, 2010

The challenge of an XProc GUI

I’ve been thinking lately about what a sleek UI for creating XProc would look like. There’s plenty of big-picture inspiration to go around, from Yahoo Pipes to Mac OSX Automator, but neither of these are as XML-focused as something working with XProc would be.

XML, or to be really specific, XML Namespaces, comes with its own set of challenges. Making an interface that’s usable is no small task, particularly when your target audience includes the 99.9% of people that don’t completely understand namespaces. Take for example a simple step, like p:delete.

In brief, that step takes an XSLTMatchPattern, following the same rules as @match in XSLT, which ends up selecting various nodes from the document, then returns a document without any of those nodes. An XSLTMatchPattern has a few limitations, but it is a very general-purpose selection mechanism. In particular, it could reference an arbitrary number of XML Namespace prefix mappings. Behind a short string like a:b lies a much longer namespace URI mapping to each prefix.

What would an intuitive user interface look like to allow entry of these kinds of expressions? How can a user keep track of unbound prefixes and attach them properly? A data-driven approach could help, say offering a menu of existing element, attribute, or namespace names taken from a pool of existing content. But by itself this falls short in 1) richer selectors, like xhtml:p[@class = “invalid”] and 2) doesn’t help in the general case, when the nodes you’re manipulating might have come from the pipeline, not your original content. (Imagine one step in the pipeline translates your XML to XHTML followed by a delete step that cleans out some unwanted nodes).

So yeah, this seems like a Really Hard Problem, but one that’s worth taking a crack at. If this sounds like the kind of thing you’d enjoy working on, my team is hiring–drop me a note.


Friday, April 2nd, 2010

Recalibrating expectations of XML performance

Working at MarkLogic has forced me to recalibrate my expectations around XML-related performance issues. Not to brag or anything, but it’s screaming fast. Conventional wisdom of avoiding // in paths doesn’t apply, since that’s the sort of thing the indexes are made to do, and that’s just the start. Single milliseconds are now a noteworthy amount of time for something showing up in the profiler.

This is what XML was supposed to be like. Now that XML has fallen off the hype cycle, we’re getting some serious work done. -m